I turned 3 BTC into 10 BTC on just-dice by betting at 33% (3x payout), starting at 0.0001 BTC, doubling each time I lose, and resetting when I win. I got really lucky.
I actually had started with 0.43 BTC a few days before, got it up to 1 BTC, invested it, went to bed, then I was playing 33% starting with smaller amounts... had a run of losses, tried to change chance to 49.5% and bet 0.1, but I typed 49.5 in the payout box, so it was 49.5x, but it still won! 4.85 BTC profit from a single bet due to a mistake.
With 6 BTC total at that point, I donated like 0.65 BTC to a site and a friend, and then I lost like 2.45 BTC playing on JD. Then I was like, well, I'm not going to do much with this 3 BTC just sitting here... and one of my friends offered to match 6 BTC so I could buy a computer. So, I set my bot to go from 3 to 6 BTC. It did. Then he was like, $600 is a lot of money, so I set the bot to go from 6 to 10 BTC.
I'm still not sure how I got this lucky.